1. Field of the Invention
The invention relates to an electro-erosion machine with an essentially cylindrical tank for holding a liquid dielectric. The cylinder is divided longitudinally into at least two sections.
In die-sinking machining, material is removed and rinsed with a liquid dielectric inside a tank that is either entirely enclosed or open at the top, and at least partly full of the dielectric.
To ensure adequate flushing, any particles removed from the electrodes (the work and the excavator) are filtered out of the dielectric, and the dielectric is cooled. The dielectric is pumped into and out of the tank.
One significant determinant of a satisfactory dielectric tank is access to the machining point.
State-of-the-art electro-erosion machine features a wide variety of dielectric tanks. Most of them prevent direct access to the machining point, and many are highly complicated.
2. Discussion of the Prior Art
An electro-erosion machine is known from German A 3 303 758 (Schiess). The front wall of its upright stand simultaneously constitutes the rear wall, and the work support the bottom, of a rectangular dielectric tank. The other sections of the wall slide up and down. Such a machine provides very satisfactory access to the work support once the tank has been lowered, which facilitates automation, although it is relatively complicated. In the other embodiments described in the same document it is only separate components of the dielectric tank, the door for example, that move, sliding up and down or swinging in one or more directions on hinges. The tank is preferably sealed with inflatable seals. The dielectric tanks described in A 3 303 758 are, with their sliding or swinging door, relatively complicated to manufacture, and allow only limited access to the work support. They render the overall machine (or plant) difficult to monitor and inhibit rapid machining.
German C 3 444 390 (AGIE) describes an electro-erosion machine incorporating a dielectric tank that also travels up and down. This design is an improvement over the one described in German A 3 444 390.
European Patent 0 347 716 (AEG) describes an electro-erosion machine with a dielectric tank that has accordion walls. It is also complicated. It is too high, and the work-support guides are too far from the surface of the work, which further compromises precision.
Electro-erosion machine with completely enclosed essentially cylindrical dielectric tanks is known from U.S. Pat. No. 3,647,669 (Kelso), U.S. Pat. No. 3,677,928 (Fleury), German A 3 246 776 (Daimler), European A 0 132 935 (Inoue), French A 2 069 863 (Amsted), and French A 2 589 375 (Renault). Access into these tanks is admittedly very limited in that the walls cannot be opened.
German A 2 540 664 (Langmatz) discloses generic electro-erosion machine that also has a cylindrical dielectric tank. The wall is attached to the bottom of the tank by magnets. The tank is sealed by an inflatable hose. The tank in one version of the machine is composed of separate parts secured together at a T joint.
Electro-erosion machining requires not only the precisely controlled removal of high volumes of material while leaving a smooth surface but also as much automation and as continuous an operation as possible. A dielectric tank with limited access can make the machine difficult to load and necessitate turning it off to "re-equip."